Chromatography Forum

Hi,

I am going to be receiving a normal phase method for analyzing a phosolipid-like analyte. The mobile phase is 2-propanol:hexane:water, 52:40:8, (v/v/v). The column is 3 um, 4.6x33 mm silica gel. I have never run a normal phase method. Are there any special things that I need to consider before I start running this method? My instrument is plumbed with stainless steel tubing so I wouldn't think that the solvents would harm the instrument. Anything else that I should think about?

Thanks,

KarenJ

For change over from Reverse-phase to normal phase following precautions should be taken,

1. Wash your system properly with water ( preferably hot ) to remove any buffer from the system.
2. flush HPLC system ( all chennels) with propanol for few hrs to get rid of water from the system.
3. make sure your pump seals and valves are OK as they may not work in normal phase solvents.
4. Use better quality of normal phase solvents if you are working at lower UV nm.

Good luck

JM

JM: No need to flush the water out, since she is using 8% water in the mobile phase.

I have had good luck chromatogaphing phospholipids by reverse phase LC-MS using either pure methanol or a mixture of acetonitrile/methanol.

The %methanol needs to be greater than 75%.

see http://users.chartertn.net/slittle/ , top section on matrix effects